General classification

General classification

There are several variables in dial indicators:

    Analog versus digital/electronic readout (most are analog)
    Dial size. Typically referred to be American Gauge Design Specification (AGD):

AGD     Diameter range (in)     Diameter range (mm)
0     1 > 1-⅜     25 > 35
1     1-⅜ > 2     35 > 50
2     2 > 2-⅜     50 > 60
3     2-⅜ > 3     60 > 75
4     3 > 3-¾     76 > 95

    Accuracy
    Range of travel
    Number of dial revolutions
    Dial style: balanced (e.g., -15 to 0 to +15) or continuous (e.g., 0 to 30)
    Graduation style: positive numbers (clockwise) or negative numbers (counterclockwise)
    Revolution counters, which show the number of revolutions of the principal needle.